Marguí E, Iglesias M, Queralt I, Hidalgo M
Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona, Spain.
Talanta. 2007 Oct 15;73(4):700-9. doi: 10.1016/j.talanta.2007.04.051. Epub 2007 May 10.
A methodology for a precise and accurate determination of lead isotope ratios in mining wastes by inductively coupled plasma quadrupole-based mass spectrometry (ICP-QMS) has been developed. The study of instrumental bias factors led to the conclusion that internal correction to compensate mass discrimination is required as well as an interference equation correction when Hg is present. The proposed method has been applied to determine lead isotope ratios in several mining wastes, soils and sediments collected at three mining areas in Spain (Aran Valley, Cartagena and Osor). Statistical analysis highlights that (206)Pb/(207)Pb and (208)Pb/(207)Pb lead isotope ratios can be used as a fingerprint of mining waste origin which is related to the geological age of the lead ore. On the other hand, no statistically significant isotopic differences between original ore samples (galena) and processing wastes within a mining district were found, corroborating a unique lead source. Moreover, the lead isotopic composition of soil and sediment samples collected at the studied mining areas is close to that determined in the mining tailings from the same areas, suggesting that the unusual high content of lead in these samples is derived from mining activities rather than from other lead sources.
已开发出一种通过基于电感耦合等离子体质谱仪（ICP-QMS）精确测定采矿废料中铅同位素比率的方法。对仪器偏差因素的研究得出结论，除了在存在汞时进行干扰方程校正外，还需要进行内部校正以补偿质量歧视。所提出的方法已应用于测定在西班牙三个矿区（阿兰山谷、卡塔赫纳和奥索尔）采集的几种采矿废料、土壤和沉积物中的铅同位素比率。统计分析表明，（206）Pb/（207）Pb和（208）Pb/（207）Pb铅同位素比率可作为与铅矿石地质年代相关的采矿废料来源的指纹。另一方面，在一个矿区内，未发现原矿样品（方铅矿）与加工废料之间存在统计学上显著的同位素差异，这证实了铅源的唯一性。此外，在研究矿区采集的土壤和沉积物样品的铅同位素组成与同一地区采矿尾矿中测定的组成相近，这表明这些样品中异常高的铅含量源自采矿活动而非其他铅源。
